1. Field of the Invention
This invention relates generally to tools for mounting electrical boxes and more particularly to a tool that allows the simultaneous alignment of two commercial electrical boxes on each side of a stud.
2. Prior Art
To properly install commercial electrical boxes three parameters must be satisfied: proper height, depth and uniformity. To be feasible the method of installation must also be economical. There have been a number of designs for installing residential outlet boxes, which generally provide some method of maintaining a proper depth of the outlet box from the front of a stud and also maintaining the proper height of the outlet with respect to the floor.
The prior art generally addresses residential outlet boxes, such as U.S. Pat. No. 4,290,591 issued to Smith. Commercial outlet boxes are of a special type and are used in commercial construction. Whereas residential buildings are generally wired using Romex wiring, commercial buildings must by code have conduit between all the electrical boxes. Commercial electrical boxes are larger than residential electrical boxes and two distinct sizes are used: 4 inch and 4 11/16 inch square. Larger conduit can be used with the 4 11/16 inch square box than with the 4 inch square box and more cubic inch capacity is provided.
There are special mounting problems associated with mounting commercial electrical boxes. The first unique problem is that often two commercial boxes are mounted side by side on either side of a stud, which can be made of either wood or metal. One box might be used for electrical distribution, while the other box is used for communications such as telephone and computer links. For the appearance of the boxes to be attractive the two boxes must have the same centerline. In other words the center of a 4 inch square box mounted on one side of a stud and the center of a 4 11/16 inch square box mounted on the other side of the stud should have equal height above some fixed plane such as a level floor. This is quite different than residential electrical boxes which are generally not mounted side by side. Also residential boxes are generally all of the same height with different widths so if they are mounted side by side it is generally just their height that needs to be equal with respect to a reference - not their centers.
The various commercial electrical boxes within a room must be aligned the same or the unattractive variance will be immediately apparent.
For commercial electrical boxes the front edge of the box must be set back just 1/8 inch behind the front of the stud. This accounts for the thickness of the flange of a plaster ring, which is mounted onto the commercial electrical box after the wiring is complete. The plaster ring protrudes beyond the stud to be even with the outside of the drywall or plaster later applied over the studs. This is different than a residential electrical box whose front edge is generally mounted to protrude beyond the front of the stud to the depth of drywall or plaster to be applied.
Presently, commercial electrical boxes are aligned by hand. Just quick measurements are performed and the boxes attached. Since the electrical work is done at a fixed price there is generally a rush to complete the work. This leads to a situation where the boxes are poorly aligned. The boxes can end up at different heights with side by side boxes misaligned. Misalignment can also occur with the boxes not at the correct depth or at an angle not aligned with the stud, so that one edge such as the top edge of the box is tipped with respect to the bottom edge.
Exasperating these problems is the fact that often the floor of a commercial building may not be level; however, the ceiling of commercial buildings are usually set by a laser, which assures exact elevations. Due to the inconvenience of making quick measurements from the ceiling, this is not now done as a matter of practice.
Therefore, a need exists for a device which solves these and other problems arising during the installation of commercial electrical boxes.